Damage mode identification of open hole composite laminates based on acoustic emission and digital image correlation methods

This paper focuses on damage mode identification of composite laminates based on acoustic emission and digital image correlation methods. The effect of different fiber/matrix materials on the damage progression of quasi-isotropic laminates with one open hole was investigated first. The effect of different hole orientations with respect to load direction on the damage mechanism of laminated composites with two interacting holes was studied next. For this purpose, correlation and Principal Component Analyses (PCA) were performed to select the most effective acoustic emission (AE) parameter in clustering. After performing PCA, peak frequency parameter was selected to cluster acoustic emission signals due to its great contribution to the principal component. Damage mechanisms were identified based on cumulative counts and energy parameters of AE events for both aspects mentioned above. The findings of the AE measurement were successfully verified by digital image correlation (DIC) measurements.